Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=false and destructiveHint=false, so the mutation nature is known; the description adds the email-flow context (code vs. link). It does not disclose failure behavior for an invalid/expired code or any prerequisites, so it only modestly exceeds the annotation baseline.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single front-loaded sentence naming the action and the required argument, with the alternative in a compact parenthetical. No wasted preamble, though the parenthetical slightly dilutes focus.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the burden falls on the description, which adequately covers the action, the input credential, and the alternative link flow. It omits what a successful confirmation returns and error handling, leaving a minor gap for a mutation tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so both parameters are already documented in the schema, including the 6-digit code and optional api_token. The description echoes the code format but adds no new parameter meaning beyond the structured fields, matching the baseline 3.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb (confirm) and resource (human's notification email) with the required credential (6-digit code). It implicitly distinguishes itself from siblings like set_notification_email and remove_notification_email by describing the confirmation step, though it never names them.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It tells the agent the trigger context (a confirmation email has arrived with a 6-digit code) and offers the alternative path (the human opening the link). It gives no explicit when-not-to-use guidance, so it falls short of a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.